The present invention relates to a paved road surface reproducing apparatus for remedying a road paved with a bituminous material at the site.
Generally speaking, the paved road having its bituminous material had aged to lose its paving function is remedied so as to prevent a danger to the runs of vehicles or environmental pollution of the roadsides. The remedy of the bituminized road has been conducted in the prior art by one of the method of digging the paved road to its full thickness to repave the dug road with a new material, the method of cutting away only the portion having lost the paving function to repave the cut portion with a new bituminous mixture, the method of raising the paved road merely with a new bituminous mixture, or the method of executing the remedy by individually using several machines such as a road surface heater, a scarifier, a screed or a roller. However, these engineering methods are followed by several problems that the time for the remedy is elongated, that the remedy is troubled by noises, that it is difficult to retain places for disposing the pavement wastes forming part of industrial wastes, and that those many machines are required to make the works inefficient and to raise the pavement cost.
In order to solve these problems, the present applicant has heretofore proposed a heating type bituminized road surface reproducing apparatus which has an effect that it can heat and scarify the road to effect the remedy by itself at the site for a short time period with inviting neither the noises and vibrations nor the industrial wastes to reproduce a paved road with economy of power and resources. Thus, in the case of the repaving method in which the bituminized road is overlaid by the bitumen, in order to transport, level, finish and tamp the new bituminous mixture, a dump truck, an asphalt finisher, a roller and so on are used to raise the problems that the many machines are required for individual works and that the cost for the remedy is raised. Since the new bituminous mixture has to be unloaded from the dump truck in accordance with the relatively slow working speed of said reproducing apparatus, moreover, this apparatus is followed by the problems that the working efficiency of said dump truck and the subsequent standby truck is bad and that the temperature drop of the new bituminous mixture is invited to deteriorate the tamping percentage of the bituminized road. In the overlaying case of that reproduced paved road at the site where the remedy is conducted at one side of the road while traffic is allowed at the other roadside, both the long line of those working machines including the standby dump truck or trucks and the intrusion of the dump truck having gained its turn into the working site in front of the reproducing apparatus raise problems that the ordinary traffic is remarkably obstructed and that the heated mixture and road surfaces have their temperatures dropped. On the other hand, the aforementioned heating type bituminized road surface reproducing apparatus has a problem that it finds it difficult to adopt the remixing method by which the bituminous mixture reproduced at the site is mixed with a new one.
In accordance with the prior art, the heating type bituminized road surface reproducing apparatus is equipped: in an upper front portion of its self-propelled body with a hopper for receiving a paving material; below the hopper with a bar feeder for feeding the paving material backward; below the center of the body with a scarifier for digging up the paved road and a rotor for breaking up the paved road dug up; and in a rear lower portion of the body with a screw spreader for spreading the paving material to have a predetermined width and thickness and a screed for tamping the paved road.
However, the aforementioned heating type bituminized road surface reproducing apparatus of the prior art is accompanied by the following problems when it digs up the paved road by the scarifier, breaking up the dug road by the rotor, feeds a new paving material backward from the hopper, levels the material by the screw spreader, and tamps the same by the screed.
It is ordinary to slope the widthwise center of the road surface upward, and there arises a difficulty that the paving material to be fed backward by the bar feeder drops in front of the screw spreader so that it flows out forward and sideway of the road surface before it is tamped by the screed.
This difficulty is severe especially in case the roadsides are formed with side grooves so that the paved surface is dug from above the side groove frames. This is because the screed has its lower face leveled with the upper faces of the side groove frames whereas the screw spreader is positioned above the face of the screed so that the soft asphalt mixture flows forward below the screw spreader until it flows down to the roadsides in accordance with the slope of the road surface. This outflow of the paving material to the side grooves makes the post-treatment difficult.